Evaluate breaking strength of thin silicon die by ball-on-ring microforce tests and finite element analysis

Through Silicon Via Multi-Chip Packaging (TSV MCP) is the current important direction for advance packaging technique. TSV/MCP need to support with thin wafer so that the stacking dies could maintain the spacing limitation, however one failure die could cause whole packaging failure that could lead to lower the yield rate and increasing the manufacturing cost. To realize the relationship between the manufacturing condition and the thin wafer strength, specialized experimental methods and tools must be developed to carry out thin wafer breaking strain/stress. In this paper, newly developed Ball-On-Ring test were set up and carried out to measure the force-displacement relation of various wafer thickness. The results from the testing then coupled with finite element analysis to reverse finding the breaking stress/strain as a function of wafer thickness. The die strength limit from this research can further support the engineer to evaluate reliability performance of the TSV MCP.